One of the many benefits of the Internet is the ability to transfer information electronically between computers with relative ease. For example, with the popularity of the World Wide Web, transferring or downloading a file from a server to a client can be as simple as selecting the file and entering a command to download the file. However, in order to perform a file transfer of this type, both the file source computer and the file destination computer must have the appropriate and compatible software to establish a connection between the computers, to properly format the file to be transferred, and to perform the actual file transfer itself.
Electronic mail, or e-mail, has also become a popular method of communication between computers connected by the Internet. In a typical e-mail system, an e-mail client allows a user to compose a text message, generally via a visual graphic user interface. The e-mail client then interacts with a mail server that forwards the mail, via the Internet to a designated recipient. The standard protocol used for sending Internet e-mail is called SMTP, which is an acronym “Simple Mail Transfer Protocol” and the sending e-mail server is called an SMTP server. When an e-mail client sends an e-mail message, the sender's computer routes the message to an SMTP server. The server examines the e-mail address in the message, and then forwards the message to the recipient's mail server. An SMTP server works in conjunction with a POP server. POP stands for Post Office Protocol and the POP server at the recipient's computer receives e-mail messages from the SMTP server. After receiving an e-mail message, the POP server stores it until the addressee retrieves it.
An e-mail system makes it simple to send and receive text messages. Generally, e-mail systems are able to transmit and receive non-text based “attachments” by encoding files of binary information (such as pictures or images) according to a MIME (Multipurpose Internet Mail Extension) specification so that they appear to be text. For example, when an e-mail server sends an e-mail message with a binary file attachment, the server first retrieves the file from its storage location and then uses a software utility that converts the binary file into a file that is composed of text characters, such as ASCII characters. The “text” file can then be included as part of a text e-mail message. When the message is received, the recipient, or their e-mail program, runs decoding software to convert the “text” file to the original binary file format.
Because binary file attachments are converted into files using text characters, attachments result in a 33% larger file when encoded with Base64 encoding, which is the de facto standard. Large e-mail messages must still be downloaded from the recipient's mail server to the mail client, thereby resulting in sizable download times. In order to manage the download times, many mail systems, especially those systems that operate with low bandwidth Internet systems, such as dial up systems, limit the size of attachments to a predetermined maximum size, for example two megabytes. Any attachments over the predetermined size are either removed by the e-mail server or the e-mail server might refuse to deliver the entire message. This can be a problem for users who regularly sent large attachments, such as multimedia content.
In order to circumvent this problem, file transfer systems that operate outside of the regular e-mail system have been developed. Typically, these systems are server based. A user who wishes to transfer a large file to a recipient first sends the file to a special file server and receives a link to the file from the gateway. The user then sends an e-mail to the recipient with the link as an attachment. When the recipient receives the e-mail with the link, he or she uses the link to navigate to the file server and then download the file from the file server. The file may be encrypted by the file server before downloading.
A problem with the aforementioned systems is that the server becomes a bottleneck, since generally large files must be first uploaded to it, perhaps encrypted and then downloaded from it, often over low bandwidth links. Therefore, there is a need for a simpler file transfer system that does not require uploading a file to a server.